517542011-09-01 19:48:01 +0000Tomcat7 filters from conf/web.xml are applied after filters defined in WEB-INF/web.xml2014-02-17 13:51:18 +0000111UnclassifiedTomcat 7Servlet & JSP API7.0.19PCLinuxRESOLVEDWONTFIXP2normal---1charlesk40devareese0oldest_to_newest1489640charlesk402011-09-01 19:48:01 +0000The behavior of filter ordering for default web.xml (i.e conf/web.xml) and the application filters in WEB-INF/web.xml has been changed from Tomcat 6 to Tomcat 7.
As you can see from the start method in http://www.docjar.com/html/api/org/apache/catalina/startup/ContextConfig.java.html it processes the default web.xml first
and then the application web config. This makes the filters from the default web.xml excuted before the application provided filters. We were heavily relying on this behavior for processing the filters.
1040 /**
1041 * Process a "start" event for this Context.
1042 */
1043 protected synchronized void start() {
1044 // Called from StandardContext.start()
1045
1046 if (log.isDebugEnabled())
1047 log.debug(sm.getString("contextConfig.start"));
1048
1049 // Set properties based on DefaultContext
1050 Container container = context.getParent();
1051 if( !context.getOverride() ) {
1052 if( container instanceof Host ) {
1053 // Reset the value only if the attribute wasn't
1054 // set on the context.
1055 xmlValidation = context.getXmlValidation();
1056 if (!xmlValidation) {
1057 xmlValidation = ((Host)container).getXmlValidation();
1058 }
1059
1060 xmlNamespaceAware = context.getXmlNamespaceAware();
1061 if (!xmlNamespaceAware){
1062 xmlNamespaceAware
1063 = ((Host)container).getXmlNamespaceAware();
1064 }
1065
1066 container = container.getParent();
1067 }
1068 }
1069
1070 // Process the default and application web.xml files
1071 defaultWebConfig();
1072 applicationWebConfig();
So, now with Tomcat 7, its different.
Merging mechanism seeing in Tomcat 7 looks as follows in general:
From http://svn.apache.org/repos/asf/tomcat/tc7.0.x/trunk/java/org/apache/catalina/startup/ContextConfig.java
1) Create appWebXml for /WEB-INF/web.xml
2) Create globalWebXml for conf/web.xml
3) orderedFragments are merged to appWebXml ( Merge web-fragment.xml files into the main web.xml)
4) globalWebXml is merged to appWebXml (which means that list of global filters are added to existing application
defined filters)
After going through the Servlet API specs for 2.5 and 3.0, I didn't find anything related to how default web.xml and application provided web.xml should be ordered. (Did I miss anything?)
There is a deployment descriptor fragments introduced in 3.0 but it applies to web.xml and the web-fragment.xml.
Changes in the ordering of filters from Tomcat 6 to 7 creates a lot of issues for us. Can this be fixed in Tomcat 7? If not, can you provide any suggestions for workaround?1489851markt2011-09-02 13:10:56 +0000The short answer is that this can't be fixed. The comment at the beginning of the webConfig() methods explains why (there were a number of spec breaking bugs introduced by trying to process the global web.xml file earlier).
I am not aware of the spec even mentioning default web.xml settings provided by the container. This is likely to vary from container to container.
I would suggest the following:
- Define a ServletContextListener in conf/web.xml
- Use this to add the filters programmatically during the contexInitialized()
- Use the isMatchAfter parameter of the addMappingXXX methods of FilterRegistration to insert the filters before those defined in any web.xml
Bugzilla isn't really the place to go into details on exactly how to do this. If the above isn't enough, please use the Tomcat users mailing list for further advice.